audio to midi? It's done! - No, I doubt that!

[Stephan M. Sprenger]

Daniel Schmitt wrote:
> 
> Michal Jurewicz wrote:
> >
> > I was wondering if there is any software out there that would convert audio
> > (let's say pcm) to midi. In other words: if I can record a real piano... 
> > [snipped by Daniel]
>
> http://www.nerds.de/nerds/data/piano.mid
> This is a real-time conversion.
> 
> We just started a free beta programm for our product Inst2midi.
> It's a audio to midi real-time conversion program for SGI platform.
> (Windows is anticipated next year.)

Are you really talking about polyphonic audio to MIDI conversion for 
_polytimbral_ music? I don't find any polyphonic polytimbral examples on 
your web site. I see on your web site either monophonic lines, which are 
fairly easy to transcribe (even if they do not have a prominent 
fundamental frequency they can be easily tracked by short time 
autocorrelation or AMDF methods) and the piano.mid polyphonic 
monotimbral example. For monophonic pitch to MIDI, as far as I remember 
Roland did this back in the 80s (anyone remember the name of that 19" 
rack unit, something with a '70' in the name, 'VP-70' maybe?), and 
probably someone else came up with a box to do this even earlier.

> You will find there a lot of examples of the converted midi file and the
> orginal audio file.
> 
> Every comment is welcome.

The one example of polyphonic monotimbral pitch to MIDI conversion goes 
in the right direction, but it still seems too unstable to work with an 
arbitary audio file (false triggerings are still too frequent and time 
resolution seems to be too coarse, ie. some events appear 'quantized' to 
the same frame). I'll compare it with what I did based on sinusoidal 
modeling back then on the SGI myself (I need to dig in my files that 
have been sitting there for almost seven years now) and I'll make the 
result available if anyone is interested and if you would allow me to 
use your piano.aiff audio file.

Best regards

Stephan M. Sprenger
Director, R&D                                  http://www.prosoniq.com
PROSONIQ PRODUCTS SOFTWARE                     http://www.sonicworx.com